Method and apparatus for processing data corresponding to fingerprint image

ABSTRACT

Provided is a method of processing data corresponding to a fingerprint image including obtaining first image data corresponding to a group including a plurality of pixels, and dividing the first image data into second image data corresponding to each of the plurality of pixels based on a plurality of weights corresponding to the plurality of pixels, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/445,417, filed Jun. 19, 2019, which claims priority from KoreanPatent Application No. 10-2018-0090406, filed on Aug. 2, 2018, andKorean Patent Application No. 10-2018-0166604, filed on Dec. 20, 2018 inthe Korean Intellectual Property Office, the disclosures of which areincorporated herein in their entireties by reference.

BACKGROUND 1. Field

Example embodiments of the present disclosure relate to a method andapparatus for processing data corresponding to a fingerprint image.

2. Description of the Related Art

The need for individual authentication using unique features ofindividuals such as fingerprints, voice, faces, hands or irises has beengradually increasing. Individual authentication functions are mainlyused in financial devices, access control devices, mobile devices,laptops, etc. Recently, since mobile devices such as smartphones havebeen widely used, fingerprint recognition devices for individualauthentication have been adopted for the protection of large amounts ofsecurity information stored smartphones.

A fingerprint detection apparatus having a high resolution and highsensitivity is required since the accuracy requirement standards offingerprint detection have increased.

SUMMARY

One or more example embodiments provide methods and apparatuses forprocessing data corresponding to a fingerprint image.

One or more example embodiments provide a non-transitorycomputer-readable recording medium having recorded thereon a program forexecuting the methods in a computer.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of example embodiments.

According to an aspect of an example embodiment, there is provided amethod of processing data corresponding to a fingerprint image, themethod including obtaining first image data corresponding to a groupincluding a plurality of pixels, and dividing the first image data intosecond image data corresponding to each of the plurality of pixels basedon a plurality of weights corresponding to the plurality of pixels,respectively.

The plurality of weights may be determined based on a plurality ofmutual capacitances between driving electrodes and detection electrodesrespectively corresponding to the plurality of pixels.

The plurality of weights may include a matrix of percentage values basedon a combination of the plurality of mutual capacitances.

The matrix may represent a distribution of the percentage values of theplurality of mutual capacitances based on a maximum value of a mutualcapacitance among the plurality of mutual capacitances.

The dividing may include obtaining values corresponding to the secondimage data by combining values corresponding to the first image datawith the plurality of weights.

The obtaining may include sequentially applying a driving signal to eachof a plurality of driving electrodes included in the group, andobtaining the first image data based on a plurality of electricalsignals measured from a plurality of detection electrodes included inthe group.

The method may further include determining a mutual capacitance at eachof a plurality of nodes where each of a plurality of driving electrodesincluded in the group and each of a plurality of detection electrodesincluded in the group intersect.

The determining may include determining a mutual capacitance in a secondchannel based on a mutual capacitance in a region including a firstchannel and the second channel, wherein a fixed potential is applied tothe first channel, and wherein the second channel is adjacent to thefirst channel.

The method may further include generating the fingerprint image based onthe second image data.

A non-transitory computer-readable recording medium having recordedthereon a computer program, which, when executed by a computer, mayperform the method.

According to an aspect of an example embodiment, there is provided adata processing apparatus including at least one processor configured toexecute instructions in a computer program, and at least one memorystoring at least a part of the computer program, wherein the at leastone processor is further configured to obtain first image datacorresponding to a group including a plurality of pixels and divide thefirst image data into second image data corresponding to each of theplurality of pixels based on a plurality of weights corresponding to theplurality of pixels, respectively.

The plurality of weights are determined based on a plurality of mutualcapacitances between driving electrodes and detection electrodesrespectively corresponding to the plurality of pixels.

The weights may include a matrix of percentage values corresponding to acombination of the plurality of mutual capacitances.

The matrix may include a distribution of the percentage values of theplurality of mutual capacitances based on a maximum value of a mutualcapacitance among the plurality of mutual capacitances.

The at least one processor may be further configured to obtain valuescorresponding to the second image data by combining values correspondingto the first image data with the plurality of weights.

The at least one processor may be further configured to sequentiallyapply a driving signal to each of a plurality of driving electrodesincluded in the group, and obtain the first image data based onelectrical signals measured from a plurality of detection electrodesincluded in the group.

The at least one processor may be further configured to determine amutual capacitance at each of a plurality of nodes where each of aplurality of driving electrodes included in the group and each of aplurality of detection electrodes included in the group intersect.

The at least one processor may be further configured to determine amutual capacitance in a second channel based on a mutual capacitance ina region including a first channel and the second channel, wherein afixed potential may be applied to the first channel, and the secondchannel may be adjacent to the first channel.

The at least one processor may be further configured to generate afingerprint image based on the second image data.

According to an aspect of an example embodiment, there is provided adata processing apparatus including at least one processor configured toexecute instructions in a computer program, at least one memory storingat least a part of the computer program, a transmission circuitconfigured to provide driving signal to a plurality of drivingelectrodes, and a reception circuit configured to determine electricsignals from a plurality of detection electrodes that cross theplurality of driving electrodes, wherein the at least one processor isfurther configured to obtain first image data corresponding to a groupincluding a plurality of pixels and divide the first image data intosecond image data corresponding to each of the plurality of pixels basedon a plurality of weights corresponding to the plurality of pixels,respectively.

The data processing apparatus of claim 20, wherein the at least oneprocessor is further configured to generate a fingerprint image based onthe second image data.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will become apparent and more readilyappreciated from the following description of example embodiments, takenin conjunction with the accompanying drawings in which:

FIG. 1 is a diagram showing an example of a fingerprint image generatingsystem according to an example embodiment;

FIG. 2 is a flowchart showing an example of a data processing methodaccording to an example embodiment;

FIG. 3 is a diagram conceptually illustrating a mutual capacitancecorresponding to each node of a touch pad according to an exampleembodiment;

FIG. 4 is a diagram for explaining an example in which a driving signalis applied to a driving group according to an example embodiment;

FIG. 5 is a diagram for explaining an example in which a receptioncircuit measures an electrical signal at a second detection electrodeaccording to an example embodiment;

FIG. 6 shows an example in which a detection group includes twodetection electrodes according to an example embodiment;

FIG. 7 is a diagram showing an example in which a reception circuitchanges the order in which detection groups measure electrical signalsaccording to an example embodiment;

FIG. 8 is a diagram showing an example in which an activated regionincludes 3×3 channels according to an example embodiment;

FIG. 9 is a diagram for explaining an example in which a processorcalculates a mutual capacitance of a node according to an exampleembodiment;

FIG. 10 is a diagram for explaining another example in which a processorcalculates a mutual capacitance of a node according to an exampleembodiment;

FIG. 11 is a diagram for explaining another example in which a processorcalculates a mutual capacitance of a node according to an exampleembodiment;

FIG. 12 is a diagram for explaining an example in which an electrodeapplies a fixed potential to some channels among channels included in atouch pad according to an example embodiment;

FIG. 13 is a diagram for explaining an example in which an electrodeapplies a fixed potential to some channels among channels included in atouch pad according to an example embodiment;

FIG. 14 is a diagram for explaining an example in which a processorobtains first image data according to an example embodiment;

FIGS. 15A to 15C are diagrams for explaining examples of weightsaccording to an example embodiment;

FIG. 16 is a diagram for explaining an example in which a processorobtains second image data according to an example embodiment; and

FIG. 17 is a flowchart showing an example of a method of generating afingerprint image according to an example embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments which areillustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, exampleembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, exampleembodiments are merely described below, by referring to the figures, toexplain aspects.

Throughout the specification, when something is referred to as“including” a component, another component may be further includedunless specified otherwise. As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list. For example, the expression, “at leastone of a, b, and c,” should be understood as including only a, only b,only c, both a and b, both a and c, both b and c, or all of a, b, and c.

Also, as used herein, the terms “units” and “modules” may refer to unitsthat perform at least one function or operation, and the units may beimplemented as hardware or software or a combination of hardware andsoftware.

Hereinafter, example embodiments will be described in detail withreference to the accompanying drawings. In this regard, the exampleembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein.

FIG. 1 is a diagram showing an example of a fingerprint image generatingsystem 1 according to an example embodiment.

Referring to FIG. 1, the fingerprint image generating system 1 mayinclude a touch pad 100, a transmission circuit 110, a reception circuit120, a processor 130, and a memory 140. FIG. 1 may further include othergeneral purpose components besides the components illustrated.

The processor 130 and the memory 140 of the fingerprint image generatingsystem 1 shown in FIG. 1 may be provided as independent data processingsystems.

Also, the processor 130 shown in FIG. 1 may be implemented as an arrayof a plurality of logic gates, or may be implemented as a combination ofa general-purpose microprocessor and a memory storing a programexecutable in the microprocessor. Embodiments are not limited thereto,and the processor 130 may be implemented as another form of hardware.

The touch pad 100 may include a plurality of driving electrodes Tx and aplurality of detection electrodes Rx formed in a direction crossing theplurality of driving electrodes Tx. In FIG. 1, the number of the drivingelectrodes Tx and the number of the detection electrodes Rx is 10,respectively, but example embodiments are not limited thereto.

The transmission circuit 110 may include a module applying a drivingsignal to the driving electrodes Tx and a module measuring an electricsignal from the detection electrodes Rx.

The driving electrodes Tx and the detection electrodes Rx of the touchpad 100 may be formed in a direction crossing each other. FIG. 1 showsan example in which the driving electrodes Tx and the detectionelectrodes Rx are orthogonal to each other, but example embodiments arenot limited thereto. In other words, an angle between a direction inwhich the driving electrodes Tx are formed and a direction in which thedetection electrodes Rx are formed may not be 90 degrees.

The mutual capacitance between each of the driving electrodes Tx and thedetection electrodes Rx of the touch pad 100 may be changed when auser's finger approaches the touch pad 100. For example, the mutualcapacitance at each of nodes where the driving electrodes Tx and thedetection electrodes Rx intersect with each other in the touch pad 100may be changed according to a shape of a fingerprint pattern of a user.The smaller the interval between the driving electrodes Tx and theinterval between the detection electrodes Rx, the higher the resolutionof a fingerprint sensor. The touch pad 100 may further include aprotective film for protecting the driving electrodes Tx and thedetection electrodes Rx.

For example, the driving electrodes Tx and the detection electrodes Rxmay include line electrodes. Each of the driving electrodes Tx mayfurther include predetermined patterns provided between the nodes wherethe driving electrodes Tx and the detection electrodes Rx intersect. Theabove-described patterns may have various shapes such as a polygonalshape, a circular shape, etc. Likewise, each of the detection electrodesRx may further include predetermined patterns provided between theabove-described nodes.

The transmission circuit 110 may apply a driving signal to the drivingelectrodes Tx. For example, the transmission circuit 110 may apply avoltage pulse to each of the driving electrodes Tx. The receptioncircuit 120 may measure an electrical signal from the detectionelectrodes Rx. As an example, the reception circuit 120 may measure acurrent flowing in each of the detection electrodes Rx. As anotherexample, the reception circuit 120 may measure a potential of each ofthe detection electrodes Rx.

The processor 130 may generally control operations of the transmissioncircuit 110 and the reception circuit 120 included in the fingerprintimage generating system 1. For example, the processor 130 may controlmagnitude of the voltage pulse applied to each of the driving electrodesTx by the transmission circuit 110, an application time, and the like.Also, the processor 130 may control the transmission circuit 110 toapply the voltage pulse to some of the driving electrodes Tx.

The processor 130 may generate and process data related to a fingerprintusing the current or potential received by the reception circuit 120.For example, the processor 130 may generate data corresponding to afingerprint image by using the current or potential received by thereception circuit 120 and generate the fingerprint image by using pixelvalues included in the data. Hereinafter, an example in which theprocessor 130 processes data to generate a fingerprint image will bedescribed in detail with reference to FIGS. 2 to 16.

The memory 140 may store a computer program required for the operationof the processor 130. For example, processor 130 may perform anoperation according to instructions in the computer program stored inthe memory 140. The memory 140 may also store data and other informationgenerated when the touch pad 100, the transmission circuit 110, thereception circuit 120 and the processor 130 operate and may store anintermediate fingerprint image and a final fingerprint image generatedwhen the processor 130 operates. In FIG. 1, the fingerprint imagegenerating system 1 is shown as including one memory 140, butembodiments are not limited thereto. For example, the fingerprint imagegenerating system 1 may include two or more memories.

FIG. 2 is a flowchart showing an example of a data processing method.

Referring to FIG. 2, the data processing method may include operationsthat are time serially processed in the fingerprint image generatingsystem 1 shown in FIG. 1. Therefore, it will be understood thatdescriptions provided above with respect to the fingerprint imagegenerating system 1 shown in FIG. 1 apply to the data processing methodof FIG. 2.

In operation 210, the processor 130 may obtain first image datacorresponding to a group including a plurality of pixels. Here, a pixelmay include four adjacent nodes. For example, a rectangle havingvertexes of four nodes adjacent to each other may include one pixel.Also, the first image data may correspond to an image representing abody of a user who touches the touch pad 100. For example, when a user'sfinger touches the touch pad 100, the first image data may be datacorresponding to a fingerprint image of the finger touching the touchpad 100. Hereinafter, an example in which the processor 130 obtains thefirst image data will be described with reference to FIGS. 3 to 14.Specifically, example processes performed by the processor 130 ofobtaining the first image data and calculating mutual capacitancesbetween the driving electrodes Tx and the detection electrodes Rxrelated to the pixels included in the group will be described.

In operation 220, the processor 130 may divide the first image data intosecond image data corresponding to each of the plurality of pixels usingweights corresponding to the plurality of pixels. Here, a weight may becalculated based on the mutual capacitances between the drivingelectrodes Tx and the detection electrodes Rx related to the pluralityof pixels. The weight may be expressed in the form of a matrix. Elementsof the matrix may include percentage values according to a combinationof the mutual capacitances. Thus, the elements of the matrix mayrepresent distribution of a weighting function.

The processor 130 may divide the first image data into the second imagedata by using the previously calculated and stored weights correspondingto the plurality of pixels. For example, the processor 130 may dividethe first image data into the second image data by using weight valuesstored in the memory 140. For example, the weights may be stored in thememory 140 as a look-up table.

The processor 130 may calculate a weight corresponding to a pixel anddivide the first image data into the second image data by using thecalculated weight. Also, the weight stored in the memory 140 may beupdated by the processor 130. Hereinafter, an example of a weight willbe described in detail with reference to FIGS. 15A through 15C.

The first image data may be data representing the entire pixels includedin the group. Meanwhile, the second image data may be data representingeach of the pixels included in the group. For example, the processor 130may combine values corresponding to the first image data with theweights to obtain values corresponding to the second image data.

Generally, a quality of obtaining an image by a system employing acapacitive touch pad may decrease when a thickness of the touch padincreases. For example, when the touch pad is disposed in a display of adevice, passivation layer may be disposed on the touch pad. When afingerprint image of a user is generated, a difference between themutual capacitance corresponding to a ridge of a fingerprint and themutual capacitance corresponding to a valley of the ridge may beinversely proportional to the square of a thickness of the passivationlayer. Therefore, when the thickness of the passivation is greater thana certain value, it may be difficult to detect the difference in themutual capacitances of the ridge and the valley of the fingerprint.

Accordingly, the processor 130 according to an example embodiment maygroup the plurality of driving electrodes Tx and the detectionelectrodes Rx that are adjacent to each other and measure a first mutualcapacitance between the driving electrodes Tx and a second mutualcapacitance between the detection electrodes Rx, thereby obtaining thefirst image data. For example, since the difference in the mutualcapacitances due to the ridge and the valley of the fingerprint isproportional to the size of an effective electrode, a large signalproportional to the number of the driving electrodes Tx and thedetection electrodes Rx adjacent to each other may be detected.Therefore, even when a passivation layer having a thickness of a certainvalue or more, for example, a thickness of several hundreds of urn ormore, is disposed on the touch pad 100, a difference between the ridgeand the valley of the fingerprint may be greater.

However, according to the first image data, data for each of the pixelsmay not be distinguished. Therefore, the quality of the image generatedusing the first image data may be low.

The processor 130 according to an example embodiment may divide firstimage data into the second image data by using the weight correspondingto the pixel. Also, the processor 130 may generate the imagecorresponding to each of the pixels by using the second image data.Accordingly, the processor 130 may generate an image of higher quality.Hereinafter, an example in which the processor 130 divides the firstvideo data into the second video data will be described with referenceto FIG. 16 below.

FIG. 3 is a diagram conceptually illustrating a mutual capacitancecorresponding to each of nodes of the touch pad 100 according to anexample embodiment.

Referring to FIG. 3, the mutual capacitances between the drivingelectrodes Tx and the detection electrodes Rx may correspond to thenodes where the driving electrodes Tx and the detection electrodes Rxcross each other.

For example, a mutual capacitance C11 between a first driving electrodeTx1 and a first detection electrode Rx1 may correspond to a node N11where the first driving electrode Tx1 and the first detection electrodeRx1 intersect. Likewise, a mutual capacitance Cmn between an mth drivingelectrode Txm (where, m is an arbitrary natural number) and an nthdetection electrode Rxn (where, n is an arbitrary natural number) maycorrespond to a node Nmn where the mth driving electrode Txm and the nthdetection electrode Rxn intersect. Hereinafter, a mutual capacitance atthe node Nmn may mean a mutual capacitance between the mth drivingelectrode Txm and the nth detection electrode Rxn.

A plurality of channels may be defined in the touch pad 100 by thedriving electrodes Tx and the detection electrodes Rx. For example, thechannels may be rectangular regions surrounded by the driving electrodesTx and the detection electrodes Rx. Also, each of the channels maycorrespond to a node. For example, a channel CH₁₁ may correspond to thenode N₁₁.

For example, different driving signals may be sequentially applied toeach of the driving electrodes Tx to measure a mutual capacitance ofeach of a plurality of nodes. Further, electric signals may beindividually measured at each of the detection electrodes Rx. Forexample, when the mutual capacitance C₁₁ is to be measured, a drivingsignal may be applied only to the first driving electrode Tx1, and anelectric signal may be measured at the first detection electrode Rx1.Similarly, when the mutual capacitance Cmn is to be measured, a drivingsignal may be applied only to the mth driving electrode Txm and anelectric signal may be measured at the nth detection electrode Rxn.

According to the example described above, to measure the mutualcapacitance of each node, a driving signal may be applied to only onedriving electrode Tx. However, in the case of a high-resolutionfingerprint sensor, intervals between the driving electrodes Tx may bevery narrow. When the intervals between the driving electrodes Tx arenarrow, an area of the channel CH that is activated during measurementof the mutual capacitance may be reduced. When the area of the channelCH to be activated is reduced, the intensity of an obtained signal maybe weak. And, the magnitude of the mutual capacitance measured at eachof the nodes may be reduced. Thus, it may be difficult to accuratelydetect a variation of the mutual capacitance of each of the nodes.

The processor 130 according to an example embodiment may group thedriving electrodes Tx into a plurality of driving groups and control thetransmission circuit 110, thereby sequentially applying drive signals toeach of the driving groups. Here, the at least two driving electrodes Txmay be included in a single drive group.

Hereinafter, an example in which a driving signal is applied to adriving group will be described with reference to FIGS. 4 and 5according to an example embodiment.

FIG. 4 is a diagram for explaining an example in which a driving signalS1 is applied to a first driving group Gd1.

Referring to FIG. 4, the processor 130 may group the driving electrodesTx1 and Tx2 into the first driving group Gd1, and the transmissioncircuit 110 may apply the driving signal 51 to the first driving groupGd1. For example, the transmission circuit 110 may apply the samevoltage pulse to the first driving group Gd1.

In FIG. 4, the first driving group Gd1 includes the driving electrodesTx1 and Tx2, but example embodiments are not limited thereto. In otherwords, the first driving group Gd1 may include any two or more drivingelectrodes among the driving electrodes Tx.

The reception circuit 120 may individually measure signals at each ofthe plurality of detection electrodes Rx. When the first driving groupGd1 includes n driving electrodes Tx (where, n is an arbitrary naturalnumber), and the reception circuit 120 measures signals at one detectionelectrode Rx, a region activated RE₁₁ in the touch pad 100 may includenx1 channels.

For example, when the first driving group Gd1 includes the first drivingelectrode Tx1 and the second driving electrode Tx2, and the receptioncircuit 120 measures a signal S₁₁ at the first detection electrode Rx1,the activated region RE₁₁ may include two channels CH₁₁ and CH₂₂. Here,REmn denotes a region activated by an mth driving group Gd_m and an nthdetection electrode Rx_n. A signal Smn means an electric signal measuredby the reception circuit 120 when REmn is activated. GCmn denotes amutual capacitance value at REmn derived from the signal Smn.

In the example described above, the driving signal S1 may be applied tothe first driving group Gd1, and a mutual capacitance GC₁₁ in theactivated region RE₁₁ may be derived from the signal S₁₁ measured at thefirst detection electrode Rx1. The mutual capacitance GC₁₁ in theactivated region RE₁₁ may be a combination of the mutual capacitance C₁₁corresponding to the channel CH₁₁ and a mutual capacitance C₁₂corresponding to the channel CH₁₂.

As shown in FIG. 4, when the transmission circuit 110 applies thedriving signal S1 to the first driving group Gd1 in which the pluralityof driving electrodes Tx, the first driving electrode Tx1 and the seconddriving electrode Tx2, are grouped, the number of channels included inthe activated region RE₁₁ when the reception circuit 120 measures thesignal may be increased. Therefore, the intensity of the signal measuredby the reception circuit 120 may be intensified. Therefore, theperformance of the fingerprint image generating system 1 may beimproved.

When the transmission circuit 110 applies the driving signal S1 to thefirst driving group Gd1, the reception circuit 120 may sequentiallymeasure the signals in each of the plurality of detection electrodes Rx.

FIG. 5 is a diagram for explaining an example in which the receptioncircuit 120 measures an electric signal at a second detection electrodeaccording to an example embodiment.

Referring to FIG. 5, the reception circuit 120 shown in FIG. 4 maychange the detection electrodes Rx that measures signals. For example,the reception circuit 120 may sequentially change the order of thedetection electrodes Rx measuring the electrical signal. When thereception circuit 120 changes the detection electrodes Rx measuring theelectric signals, an activated region RE12 may also move. The activatedregion REnm may move in a horizontal direction when the receptioncircuit 120 changes the order of the detection electrodes Rx measuringthe electric signals.

The activated region RE may also move in the vertical direction when thetransmission circuit 110 changes the order of the driving groups Gdapplying driving signals.

Although an order is given to each of the plurality of drive groups Gdas described above, embodiment are not limited thereto, and the order inwhich the driving signals are applied may vary. For example, thetransmission circuit 110 may apply the driving signal to a third drivinggroup Gd3 after applying the driving signal to the first driving groupGd1, and apply the driving signal to a second driving group Gd2.

Also, in FIGS. 3 and 4, the driving group Gd includes the two drivingelectrodes Tx, but embodiments are not limited thereto. For example, thedriving group Gd may include k+1 driving electrodes Tx (k is anarbitrary natural number). For example, an nth driving group Gd_n (n isan arbitrary natural number) may include nth to n+kth driving electrodesTx_n, . . . , Tx_n+k.

FIGS. 3 and 4 show examples in which the reception circuit 120 outputsan electric signal from each of the plurality of detection electrodes Rxindividually. However, the embodiment is not limited thereto. Forexample, the reception circuit 120 may group the plurality of detectionelectrodes Rx into a plurality of detection groups and sequentiallymeasure electrical signals output from the plurality of detectiongroups.

Hereinafter, an example in which an electric signal of a detection groupis measured will be described with reference to FIGS. 6 and 7.

FIG. 6 shows an example in which a first detection group Gr1 includestwo detection electrodes Rx1 and Rx2 according to an example embodiment.

Referring to FIG. 6, the processor 130 may group the two detectionelectrodes Rx into the detection group Gr. The processor 130 may groupthe first and second detection electrodes Rx1 and Rx2 into the firstdetection group Gr1, and the reception circuit 120 may measure anelectrical signal output from the first detection group Gr1. That is,the reception circuit 120 may measure the electric signal obtained bysumming electric signals output from the first and second detectionelectrodes Rx1 and Rx2 included in the first detection group Gr1.

As shown in FIG. 6, when the first drive group Gd1 includes the twodriving electrodes Tx1 and Tx2, and the first detection group Gr1includes the two detection electrodes Rx1 and Rx2, the region RE₁₁activated by the first driving group Gd1 and the first detection groupGr1 may include 2×2 channels. When the processor 130 groups theplurality of detection electrodes Rx into the detection group Gr and thereception circuit 120 measures the electrical signal from the firstdetection group Gr1, the size of the activated region RE may beincreased when measuring the electric signal. Therefore, the magnitudeof the electric signal to be measured may be increased, and a mutualcapacitance of the activated region RE may be more accurately derivedtherefrom.

FIG. 7 is a diagram showing an example in which the reception circuit120 changes the order of the detection groups Gr measuring electricsignals according to an example embodiment.

Referring to FIG. 7, the reception circuit 120 may measure an electricalsignal output from a second detection group Gr2. Here, the seconddetection group Gr2 may include the second and third detectionelectrodes Rx2 and Rx3. The reception circuit 120 may sequentiallychange the order of the detection groups Gr measuring the electricsignals. A position of the activated region RE may move in a horizontaldirection when the reception circuit 120 changes the order of thedetection groups Gr measuring the electric signals. The region RE₁₂activated by the second detection group Gr2 may include the region RE₁₁activated by the first detection group Gr1 and the channels CH₁₂ andCH₂₂ overlapping with each other.

The reception circuit 120 may sequentially change the order of thedetection electrodes Rx included in the detection group Gr every timethe order of the detection groups Gr is changed. For example, thereception circuit 120 may further increase the order of the detectionelectrodes Rx included in the detection group Gr one by one each timethe order of the detection groups Gr increases one by one. That is, whenthe first detection group Gr1 includes the first and second detectionelectrodes Rx1 and Rx2, the second detection group Gr2 may include thesecond and third detection electrodes Rx2 and Rx3. That is, thearbitrary nth detection group Gd_n may include the nth detectionelectrode Tx_n and an (n+1)th detection electrode Tx_n+1.

As described above with reference to FIGS. 6 and 7, the order is givento each of the detection groups Gr. However, embodiments are not limitedthereto. For example, the reception circuit 120 may measure an electricsignal output from a third detection group Gr3 after measuring anelectric signal output from the first detection group Gr1, and measurean electric signal output from the second detection group Gr2.

Also, FIGS. 6 and 7 show examples in which the detection group Grincludes the two detection electrodes Rx, but embodiments are notlimited thereto. For example, the detection group Gr may include k+1detection electrodes Rx (k is an arbitrary natural number). For example,the nth detection group Gr_n (n is an arbitrary natural number) mayinclude the nth to n+kth detection electrodes Rx_n, . . . , Rx_n+k.

FIG. 8 is a diagram showing an example in which the activated regionRE₁₁ includes 3×3 channels according to an example embodiment.

Referring to FIG. 8, the driving group Gd may include three drivingelectrodes Tx, and the detection group Gr may include three detectionelectrodes Rx. For example, the first driving group Gd1 may include thefirst through third driving electrodes Tx1, Tx2, and Tx3, and the firstdetection group Gr1 may include the first through third detectionelectrodes Rx1, Rx2, and Rx3. The region RE₁₁ activated by the firstdriving group Gd1 and the first detection group Gr1 may include 3×3channels.

Examples of grouping the driving electrodes Tx and the detectionelectrodes Rx are described with reference to FIGS. 6 to 8 above. Theabove-described embodiments are merely examples and the embodiments arenot limited thereto. For example, the number of the driving electrodesTx included in the driving group Gd and the number of the detectionelectrodes Rx included in the detection group Gr may be different fromthe above examples.

Meanwhile, the processor 130 may calculate a mutual capacitance of eachof a plurality of nodes where the plurality of driving electrodes Tx andthe plurality of detection electrodes Rx intersect respectively, from anelectric signal measured in the reception circuit 120. For example, theprocessor 130 may include a hardware resource capable of performing anoperation of calculating the mutual capacitance of each of a pluralityof nodes.

The processor 130 may calculate the mutual capacitance of each of thenodes in consideration of positions of the nodes. For example, theprocessor 130 may differently determine a weight of a mutual capacitancemeasured in each of the plurality of driving groups Gd based on thepositions of the nodes. Also, the processor 130 may differentlydetermine a weight of a mutual capacitance measured in each of theplurality of detection electrodes Rx. That is, the processor 130 maydifferently determine a weight of the mutual capacitance GCmn in each ofthe regions Remm activated by each of the plurality of driving groupsGd_m and each of the plurality of detection electrodes Rx_n.

FIG. 9 is a diagram for explaining an example in which the processor 130calculates a mutual capacitance C₂₂ of a node N₂₂ according to anexample embodiment.

FIG. 9 shows an example where the activation region RE includes 2×1channels, as shown in FIGS. 4 and 5. Referring to FIG. 9, the regionsRE₁₂ and RE₂₂ may include the channel CH₂₂ corresponding to the nodeN₂₂. The processor 130 may calculate the mutual capacitance C12 of theregion RE₁₂ from the electric signal S₁₂ measured by the receptioncircuit 120 in the second detection electrode Rx2 when the transmissioncircuit 110 applies a driving signal to the first driving group Gd1. Theprocessor 130 may calculate the mutual capacitance C₂₂ of the regionRE₂₂ from the electric signal S₂₂ measured by the reception circuit 120in the second detection electrode Rx2 when the transmission circuit 110applies a driving signal to the second driving group Gd2.

Considering that a proportion occupied by the channel CH₂₂ in the regionRE₁₂ is ½ and a proportion occupied by the channel CH₂₂ in the regionRE₂₂ is ½, the processor 130 may calculate the mutual capacitance C₂₂ byuses Equation 1 below.

$\begin{matrix}{C_{22} = \frac{{GC}_{12} + {GC}_{22}}{2}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

The processor 130 may determine a weight of a mutual capacitance GC₁₂obtained by a combination of the first driving group Gd1 and the seconddetection electrode Rx2 as ½ as shown in Equation 1 above. Further, theprocessor 130 may determine a weight of a mutual capacitance GC₂₂obtained by a combination of the second driving group Gd2 and the seconddetection electrode Rx2 as ½. The processor 130 may determine weights ofmutual capacitance values obtained by combinations of the remainingdriving groups Gd and detection electrodes Rx other than the twocombinations as 0.

FIG. 10 is a diagram for explaining another example in which theprocessor 130 calculates the mutual capacitance C₂₂ of the node N₂₂according to an example embodiment.

FIG. 10 shows a case where the activation region RE includes 2×2channels, as shown in FIGS. 6 and 7. Referring to FIG. 10, each of theregions RE₁₁ and RE₁₂, a region RE₂₁, and a region RE₂₂ may include thechannel CH₂₂ corresponding to the node N₂₂. The processor 130 maycalculate mutual capacitances GC₁₁, GC₁₂, GC₂₁, and GC₂₂ of respectiveregions from electric signals obtained from the driving group Gr and thedetection group Gr corresponding to the regions RE₁₁, RE₁₂, RE₂₁ andRE₂₂. The processor 130 may determine a weight of each of the mutualcapacitances GC₁₁, GC₁₂, GC₂₁, and GC₂₂ as ¼, considering that aproportion of the channel CH₂₂ in each of the region RE₁₁, the regionRE₁₂, the region RE₂₁, and the region RE₂₂ is ¼.

For example, the processor 130 may calculate the mutual capacitance C₂₂using Equation 2 below.

$\begin{matrix}{C_{22} = \frac{{GC}_{11} + {GC}_{12} + {GC}_{21} + {GC}_{22}}{4}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

The processor 130 may determine the weight of each of the mutualcapacitances GC₁₁, GC₁₂, GC₂₁, and GC₂₂ obtained by a combination of thedriving group Gd and the detection group Gr corresponding to each of theregions RE₁₁, RE₁₂, RE₂₁ and RE₂₂ as ¼. The processor 130 may determinea weight of each of mutual capacitances obtained by a combination of theremaining driving group Gd and detection group Gr that do not correspondto the regions RE₁₁, RE₁₂, RE₂₁ and RE₂₂ as 0.

FIG. 11 is a diagram for explaining another example in which theprocessor 130 calculates a mutual capacitance C₃₃ of a node N₃₃according to an example embodiment.

FIG. 11 shows a case where the activation region RE includes 3×3channels, as shown in FIG. 8. Referring to FIG. 13, each of regionsRE₁₁, RE₁₂, RE₁₃, RE₂₁, RE₂₂, RE₂₃, RE₃₁, RE₃₂, and RE₃₃ may include thechannel CH₃₃. The processor 130 may calculate mutual capacitances CG₁₁,CG₁₂, CG₁₃, CG₂₁, CG₂₂, CG₂₃, CG₃₁, CG₃₂, and CG₃₃ of respective regionsfrom electric signals obtained from the driving group Gd and thedetection group Gr corresponding to each of the regions RE₁₁, RE₁₂,RE₁₃, RE₂₁, RE₂₂, RE₂₃, RE₃₁, RE₃₂, and RE₃₃. Considering that aproportion of the channel CH₃₃ in each of the regions RE₁₁, RE₁₂, RE₁₃,RE₂₁, RE₂₂, RE₂₃, RE₃₁, RE₃₂, and RE₃₃ is 1/9, the processor 130 maydetermine a weight of each of the mutual capacitances CG₁₁, CG₁₂, CG₁₃,CG₂₁, CG₂₂, CG₂₃, CG₃₁, CG₃₂, and CG₃₃ as 1/9.

For example, the processor 130 may calculate the mutual capacitance CG₃₃using Equation 3 below.

$\begin{matrix}{C_{33} = \frac{\begin{matrix}{{GC}_{11} + {GC}_{12} + {GC}_{13} + {GC}_{21} +} \\{{GC}_{22} + {GC}_{23} + {GC}_{31} + {GC}_{32} + {GC}_{33}}\end{matrix}}{9}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

The processor 130 may determine the weight of each of the mutualcapacitances CG₁₁, CG₁₂, CG₁₃, CG₂₁, CG₂₂, CG₂₃, CG₃₁, CG₃₂, and CG₃₃obtained by a combination of the driving group Gd and the detectiongroup Gr corresponding to each of the regions RE₁₁, RE₁₂, RE₁₃, RE₂₁,RE₂₂, RE₂₃, RE₃₁, RE₃₂, and RE₃₃ as 1/9 as shown in Equation 3 above.The processor 130 may determine a weight of each of mutual capacitancesobtained by a combination of the remaining driving group and detectiongroup that do not correspond to the regions RE₁₁, RE₁₂, RE₁₃, RE₂₁,RE₂₂, RE₂₃, RE₃₁, RE₃₂, and RE₃₃ as 0.

Meanwhile, the processor 130 may differently determine the weights ofthe mutual capacitances CG₁₁, CG₁₂, CG₁₃, CG₂₁, CG₂₂, CG₂₃, CG₃₁, CG₃₂,and CG₃₃. For example, since the channel CH33 is located at the centerof the region RE22, in the mutual capacitance GC₂₂ of the region RE22, acontribution ratio of the mutual capacitance C₃₃ of the node N₃₃ may behigher than other regions. Thus, the processor 130 may give more weightson the mutual capacitance GC₂₂ in the region RE₂₂. For example, theprocessor 130 may calculate the mutual capacitance C₃₃ using Equation 4below.

$\begin{matrix}{C_{33} = \frac{\begin{matrix}{{GC}_{11} + {GC}_{12} + {GC}_{13} + {GC}_{21} + {w \cdot}} \\{{GC}_{22} + {GC}_{23} + {GC}_{31} + {GC}_{32} + {GC}_{33}}\end{matrix}}{w + 8}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack\end{matrix}$

In Equation 4 above, w denotes an arbitrary real number greater than 1.In Equation 4, the larger the value of w, the larger the weight of themutual capacitance GC₂₂ in the region RE₂₂.

In the foregoing examples, the processor 130 may calculate the mutualcapacitances of the nodes by determining weights of mutual capacitancevalues in the various regions RE.

Meanwhile, the processor 130 may calculate a mutual capacitance in eachof nodes by using predetermined fixed potential values applied topredetermined channels in the touch pad 100. Hereinafter, an example inwhich the processor 130 calculates a mutual capacitance of a node byusing fixed potential values will be described with reference to FIG.12.

FIG. 12 is a diagram for explaining an example in which an electrode EDapplies a fixed potential to some of channels included in the touch pad100 according to an example embodiment.

FIG. 12 shows a calculation process of the processor 130 in a 2×1measurement method described above with reference to FIGS. 4 and 5.

Referring to FIG. 12, the fingerprint image generating system 1 mayfurther include the electrode ED applying the predetermined fixedpotential to at least two channels among a plurality of channels formedon the touch pad 100. Here, the electrode ED may include a transparentindium tin oxide (ITO) electrode.

The electrode ED may be connected to a fixed potential such as a ground.In this case, the electrode ED may equalize a potential of channels incontact with the electrode ED with a ground potential, but embodimentsare not limited thereto, for example, the ED may be connected to apotential that is not fixed. For example, the electrode ED may beconnected to a predetermined power source such that the potential of theelectrode ED may be maintained at the predetermined fixed potential bythe power source.

The electrode ED may apply the fixed potential to channels located atthe edges of the touch pad 100. For example, the electrode ED may applythe fixed potential to the uppermost channels of the touch pad 100. Whenthe electrode ED is grounded, a fixed potential value may be equal to aground potential value, but embodiments are not limited thereto. Forexample, when the electrode ED is connected to a power source, the fixedpotential value may be different from the ground potential value.

When the fixed potential of constant magnitude is continuously appliedto the uppermost channels of the touch pad 100, a mutual capacitance inthe channels to which the fixed potential is applied may not change.That is, the mutual capacitance of the channels to which the fixedpotential is applied may be fixed, regardless of whether a user's fingertouches the touch pad 100. The processor 130 may calculate a mutualcapacitance of a second channel based on a mutual capacitance in aregion including a first channel to which the fixed potential is appliedand the second channel adjacent to the first channel.

For example, the processor 130 may calculate the mutual capacitance GC₁₂in the region RE₁₂ including the channel CH₁₂ to which the fixedpotential is applied and the channel CH₂₂ adjacent to the channel CH₁₂.The processor 130 may calculate the mutual capacitance GC₂₂ in thechannel CH₂₂ by adding or subtracting a mutual capacitance in thechannel CH₁₂ having a value fixed by the fixed potential in the mutualcapacitance GC₁₂ of the region RE₁₂. The processor 130 may calculate themutual capacitance C₂₂ by using Equation 5 below.C ₂₂ =GC ₁₂ −C ₁₂   [Equation 5]

When the mutual capacitance C₂₂ is calculated from Equation 5 above, amutual capacitance C₃₂ in a channel CH₃₂ adjacent to the channel CH₂₂may be inductively calculated. For example, the processor 130 maycalculate the mutual capacitance GC₂₂ in the region RE₂₂ including thechannel CH₂₂ and a channel CH₂₃. Since the processor 130 determines avalue of the mutual capacitance C₂₂ in the channel CH₂₂ from Equation 5,the processor 130 may calculate the mutual capacitance C₃₂ in thechannel CH₃₂ by subtracting the mutual capacitance C₂₂ in the channelCH₂₂ from the mutual capacitance GC₂₂ in the region RE₂₂.

FIG. 13 is a diagram for explaining an example in which the electrode EDapplies a fixed potential to some of channels included in the touch pad100 according to an example embodiment.

FIG. 13 shows a calculation process of the processor 130 in a 2×2measurement method described above with reference to FIGS. 6 and 7.

The electrode ED may apply the fixed potential to channels located atupper and left edges of the touch pad 100. In this case, mutualcapacitance values of the channels located at the upper and left edgesof the touch pad 100 on which the electrode ED applies the fixedpotential may not change. Similar to the description provided above withreference to FIG. 12, the processor 130 may calculate the mutualcapacitance C₂₂ in the channel CH₂₂ by subtracting the previously knownmutual capacitances C₁₁, C₁₂, and C₂₁ in the channels CH₁₁, CH₁₂, andCH₂₁ from the mutual capacitance GC₁₁ in the region RE₁₁. The processor130 may also inductively calculate the mutual capacitance C₂₃ in theother channel CH23 from the mutual capacitance C₂₂ in the channel CH₂₂.

As described above with reference to FIGS. 3 to 13, the processor 130may group the driving electrodes Tx and the detection electrodes Rx suchthat the region RE to be activated in the touch pad 100 upon measuring asignal is increased. Since an area of the region RE to be activatedincreases, the performance of the fingerprint image generating system 1may be improved. For example, the fingerprint image generating system 1may obtain a high-quality image and improvement of sensing performance.The performance of the fingerprint image generating system 1 may also beimproved by appropriately adjusting a weight of each of the mutualcapacitances GC in the region RE when the processor 130 calculatesmutual capacitances of nodes. When the fixed potential is applied tochannels located at the edge of the touch pad 100, the processor 130 maymore accurately calculate the mutual capacitance of each of the nodes.

As described above with reference to FIG. 2, the processor 130 mayobtain first image data corresponding to a group including a pluralityof pixels. More specifically, the transmission circuit 110 may apply adriving signal to the single driving electrode Tx or the driving groupGd including a plurality of driving electrodes, and the receptioncircuit 120 may measure an electrical signal output from the singledetection electrode Rx or the detection group Gr including a pluralityof detection electrodes. Then, the processor 130 may obtain the firstimage data by using the electric signal measured by the receptioncircuit 120.

FIG. 14 is a diagram for explaining an example in which the processor130 obtains first image data S according to an example embodiment.

In FIG. 14, 5×5 pixels corresponding to the touch pad 100 are shown. Thetouch pad 100 may include five driving electrodes Tx and five detectionelectrodes Rx. Hereinafter, it is assumed that 3×3 pixels form onegroup. For example, referring to FIG. 14, it is assumed that a firstgroup 1410 includes 9 pixels X_(m,n), X_(m,n+1), X_(m,n+2), X_(m+1,n),X_(m+1,n+1), X_(m+1,n+2), X_(m+2,n), X_(m+2,n+1), and X_(m+2,n+2), and asecond group 1420 includes other 9 pixels X_(m,n+1), X_(m,n+2),X_(m,n+3), X_(m+1,n+1), X_(m+1,n+2), X_(m+1,n+3), X_(m+2,n+1),X_(m+2,n+2), and x_(m+2,n+3). However, the number of pixels included ina group is not limited to 3×3.

The processor 130 may obtain the first image data corresponding to thefirst and second groups 1410 and 1420. For example, the first image dataobtained by the processor 130 may be expressed as Equation 6 below.

$\begin{matrix}{{S_{m,n} = {\sum\limits_{i = m}^{m + p}{\sum\limits_{j = n}^{n + q}{w_{i,j}x_{i,j}}}}},\left( {{m = 1},2,\ldots\mspace{14mu},{{M\text{;}\mspace{14mu} n} = 1},2,\ldots\mspace{14mu},N} \right)} & \left\lbrack {{Equation}\mspace{20mu} 6} \right\rbrack\end{matrix}$

In Equation 6 above, S denotes the first image data, and x denotes avalue of a single pixel. Also, w denotes a weight corresponding to thesingle pixel. Also, p and q denote values obtained by subtracting 1 fromthe number of pixels in a row direction and subtracting 1 from thenumber of pixels in a column direction in the first and second groups1410 and 1420, respectively. For example, according to the first andsecond groups 1410 and 1420 shown in FIG. 14, p and q correspond to 2,respectively.

In Equation 6, the first image data S of the first group 1410 may bedefined as the sum of products of the 9 pixels x_(m,n), X_(m,n+1),X_(m,n+2), X_(m+1,n), X_(m+1,n+1), X_(m+1, n+2), X_(m+2,n), X_(m+2,n+1),and X_(m+2,n+2) and the weight w. Also, the first image data S_(m,n+1)of the second group 1420 may be defined as the sum of products of the 9pixels X_(m,n+1), X_(m,n+2), X_(m,n+3), X_(m+1,n+1), X_(m+1,n+2),X_(m+1,n+3), X_(m+2,n+1), X_(m+2,n+2), X_(m+2,n+3) and the weight w.

As described above with reference to FIGS. 3 to 8, the reception circuit120 may measure an electrical signal with respect to an activated regionincluding a plurality of channels. Accordingly, the processor 130 mayobtain the first image data S_(m,n), S_(m,n+1) corresponding to thefirst and second groups 1410 and 1420 including the plurality of pixels.

Further, the processor 130 may obtain first image data S_(m−1, n−1), . .. , S_(m+3,n+3) with respect to each of the first and second groups 1410and 1420 as described above.

In Equation 6 above, the weight w_(i,j) may be previously calculated andstored in the memory 140. For example, the processor 130 may calculatethe weight w_(i,j) and write the calculated weight w_(i,j) to the memory140. For example, the processor 130 may calculate the weight w_(i,j)corresponding to the pixels included in the group. Specifically, theprocessor 130 may calculate the weight w_(i,j) based on mutualcapacitances between driving electrodes and detection electrodes relatedto the pixels.

FIGS. 15A to 15C are diagrams for explaining an example of weightsaccording to example embodiments.

FIG. 15A shows an example of mutual capacitances between a seventhdriving electrode Tx7 and the other driving electrodes Tx. For example,a mutual capacitance between the seventh driving electrode Tx7 and thefirst driving electrode Tx1 may be calculated as 0.129 (fF), and amutual capacitance between the seventh driving electrode Tx7 and a sixthdriving electrode Tx6 may be calculated as 10.415 (fF).

Also, FIG. 15B shows an example of mutual capacitances between a seventhdetection electrode Rx7 and the other detection electrodes Rx. Forexample, a mutual capacitance between the seventh detection electrodeRx7 and the second detection electrode Rx2 may be calculated as 0.204(fF), and a mutual capacitance between the seventh detection electrodeRx7 and an eighth detection electrode Rx8 may be calculated as 8.862(fF).

As described above with reference to FIGS. 9 through 13, the processor130 may calculate the mutual capacitance using various methods. However,the mutual capacitance values are not limited to those shown in FIGS.15A and 15B. That is, the mutual capacitance values may vary dependingon the specifications of the driving electrodes Tx and the detectionelectrodes Rx. In other words, the mutual capacitance may be determineddifferently according to the specification of the touch pad 100.

The processor 130 may calculate a weight based on the mutualcapacitances between the driving electrodes Tx and the detectionelectrodes Rx. For example, the weight may be calculated by multiplyingthe mutual capacitances between the driving electrodes Tx and the mutualcapacitances between the detection electrodes Rx.

The weight may be derived in the form of a matrix. Here, elementsconstituting the matrix may be percentage values according to acombination of mutual capacitances. In other words, an element of thematrix may be expressed as a percentage, which is a value obtained bydividing the product of a mutual capacitance between the two drivingelectrodes Tx and a mutual capacitance between the two detectionelectrodes Rx by the maximum value. Here, the maximum value may mean themaximum value of the mutual capacitances. Thus, as shown in FIG. 15B,the elements of the matrix may represent a distribution of weightingfunctions.

The processor 130 may divide the first image data S_(m,n), S_(m,n+1)into second image data corresponding to each of the plurality of pixelsby using the calculated weight. For example, the processor 130 mayobtain values corresponding to the second image data by combining valuescorresponding to the first image data S_(m,n), S_(m,n+1) and the weight.

FIG. 16 is a diagram for explaining an example in which the processor130 obtains second image data x′ according to an example embodiment.

FIG. 16 shows values corresponding to the first image data S describedabove with reference to FIG. 14. Therefore, hereinafter, it is assumedthat 3×3 pixels form one group as described above with reference to FIG.14.

Referring to FIG. 16, the processor 130 may combine the first image dataS_(m,n) and weights w_(0,0), w_(0,1), w_(2,2) to calculate second imagedata x′_(m,n), x′_(m,n+1), . . . , x′_(m+2,n+2) with respect to each of9 pixels. For example, the processor 130 may calculate the second imagedata x′_(m,n), x′_(m,n+1), . . . , x′_(m+2,n+2) using Equation 7 below.

$\begin{matrix}{x_{m,n}^{\prime} = {\sum\limits_{i = m}^{m - p}{\sum\limits_{j = n}^{n - q}{w_{{m - i},{n - j}}S_{i,j}}}}} & \left\lbrack {{Equation}\mspace{20mu} 7} \right\rbrack\end{matrix}$

Variables shown in Equation 7 may be the same as described above withreference to Equation 6 above. Referring to Equation 6, values of the 9pixels may be combined in the first image data S. Also, the first imagedata S may include an influence of mutual capacitances of the drivingelectrodes Tx and the detection electrodes Rx constituting the 9 pixels.Accordingly, the processor 130 may calculate the second image data x′with respect to each pixel by combining the weight w based on a mutualcapacitance and the first image data S, as in Equation 7.

A first group corresponding to the first image data S_(m,n) and a secondgroup corresponding to the first image data S_(m,n+1) may include pixelsthat overlap with each other. For example, since the first group and thesecond group differ by one row or one column, the first group and thesecond group may include the pixels that overlap with each other. Thus,the processor 130 may obtain the second image data x′ according toEquation 7 above with respect to all groups including a specific pixel,to obtain the second image data x′_(m,n) with respect to the specificpixel. Then, the processor 130 may finally determine the second imagedata x′_(m,n) with respect to the specific pixel by summing the obtainedsecond image data x′.

The processor 130 may generate an image using the obtained second imagedata x′.

FIG. 17 is a flowchart showing an example of a method of generating afingerprint image according to an example embodiment.

Referring to FIG. 17, the method of generating the fingerprint image mayinclude operations that are time serially processed in the fingerprintimage generating system 1 shown in FIG. 1. Therefore, it will beunderstood that descriptions provided above with respect to thefingerprint image generating system 1 shown in FIG. 1 apply to themethod of generating the fingerprint image of FIG. 17.

In operation 1710, the processor 130 may obtain first image data. Here,the first image data may be data representing a group including aplurality of pixels. For example, the processor 130 may obtain the firstimage data according to the method described above with reference toFIGS. 3 to 8 and 14.

In operation 1720, the processor 130 may obtain a mutual capacitance.For example, the processor 130 may obtain the mutual capacitanceaccording to the method described above with reference to FIGS. 9 to 13.

In operation 1730, the processor 130 may generate the fingerprint imageby using the first image data. However, operation 1730 may be omitted.

In operation 1740, the processor 130 may calculate a weight by using themutual capacitance. For example, the processor 130 may calculate theweight according to the method described above with reference to FIG.15. The processor 130 may store the calculated weight in the memory 140and use the weight stored in the memory 140 to obtain second image data.For example, the weight may be stored in memory 140 as a look-up table.

The processor 130 may calculate the weight and divide the first imagedata into the second image data by using the calculated weight. Also,the weight stored in the memory 140 may be updated by the processor 130.

In operation 1750, the processor 130 may obtain the second image databased on the calculated or stored weight. Here, the second image datamay be data representing each of pixels included in a group. Forexample, the processor 130 may divide the first image data into thesecond image data according to the method described above with referenceto FIG. 16.

In operation 1760, the processor 130 may generate the fingerprint imageby using the second image data.

According to the descriptions above, the processor 130 may divide thefirst data with respect to a plurality of pixels into the second datawith respect to each of the pixels. Therefore, a higher quality imagemay be generated than an image generated by using the first image data.Also, since the fingerprint image generating system 1 obtains the firstimage data, more precise data indicating an object touching the touchpad 100 may be obtained even when a thickness of a passivation layer onthe touch pad 100 is greater than a certain value.

The example embodiments described above may be implemented as anexecutable program, and may be executed by a general-purpose digitalcomputer that runs the program by using a computer-readable recordingmedium. Also, a structure of data used in the example embodimentsdescribed above may be recorded by using various units on acomputer-readable medium. Examples of the non-transitorycomputer-readable medium include storage media such as magnetic storagemedia, e.g., read only memories (ROMs), floppy discs, or hard discs,optically readable media, e.g., compact disk-read only memories(CD-ROMs), or digital versatile disks (DVDs), etc. but embodiments arenot limited thereto.

It should be understood that example embodiments described herein shouldbe considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exampleembodiment should typically be considered as available for other similarfeatures or aspects in other embodiments.

While example embodiments have been described with reference to thedrawings, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A method of processing data corresponding to afingerprint image, the method comprising: obtaining first image datacorresponding to a group comprising a plurality of uniformly arrangedpixels; and dividing the first image data into second image datacorresponding to each of the plurality of pixels based on a plurality ofweights corresponding to the plurality of pixels, wherein the dividingcomprises obtaining a value of the second image data based on acombination of a value of the first image data with each of theplurality of weights corresponding to the plurality of pixels includedin the group.
 2. The method of claim 1, wherein the plurality of pixelsare generated by a plurality of driving electrodes arranged to haveuniform distances from each other along a first direction and aplurality of detection electrodes arranged to have uniform distancesfrom each other along a second direction intersecting the firstdirection.
 3. The method of claim 1, wherein the plurality of weightsare determined based on a plurality of mutual capacitances betweendriving electrodes and detection electrodes constituting the pluralityof pixels.
 4. The method of claim 3, wherein the plurality of weightscomprise a matrix of percentage values based on a combination of theplurality of mutual capacitances.
 5. The method of claim 4, wherein thematrix represents a distribution of the percentage values of theplurality of mutual capacitances based on a maximum value of a mutualcapacitance among the plurality of mutual capacitances.
 6. The method ofclaim 1, wherein the obtaining comprises: sequentially applying adriving signal to each of a plurality of driving electrodes included inthe group; and obtaining the first image data based on a plurality ofelectrical signals measured from a plurality of detection electrodesincluded in the group.
 7. The method of claim 1, further comprising:determining a mutual capacitance at each of a plurality of nodes whereeach of a plurality of driving electrodes included in the group and eachof a plurality of detection electrodes included in the group intersect.8. The method of claim 7, wherein the determining comprises: determininga mutual capacitance in a second channel based on a mutual capacitancein a region comprising a first channel and the second channel, wherein afixed potential is applied to the first channel, and wherein the secondchannel is adjacent to the first channel.
 9. The method of claim 1,further comprising generating the fingerprint image based on the secondimage data.
 10. A non-transitory computer-readable recording mediumhaving recorded thereon a computer program, which, when executed by acomputer, performs the method of claim
 1. 11. A data processingapparatus comprising: at least one processor configured to executeinstructions in a computer program; and at least one memory storing atleast a part of the computer program, wherein the at least one processoris further configured to obtain first image data corresponding to agroup comprising a plurality of uniformly arranged pixels and divide thefirst image data into second image data corresponding to each of theplurality of pixels based on a plurality of weights corresponding to theplurality of pixels, and wherein the at least one processor is furtherconfigured to obtain a value of the second image data based on acombination of a value of the first image data with each of theplurality of weights corresponding to the plurality of pixels includedin the group.
 12. The data processing apparatus of claim 11, wherein theplurality of pixels are generated by a plurality of driving electrodesarranged to have uniform distances from each other along a firstdirection and a plurality of detection electrodes arranged to haveuniform distances from each other along a second direction intersectingthe first direction.
 13. The data processing apparatus of claim 11,wherein the plurality of weights are determined based on a plurality ofmutual capacitances between driving electrodes and detection electrodesconstituting the plurality of pixels.
 14. The data processing apparatusof claim 13, wherein the plurality of weights comprise a matrix ofpercentage values corresponding to a combination of the plurality ofmutual capacitances.
 15. The data processing apparatus of claim 14,wherein the matrix comprises a distribution of the percentage values ofthe plurality of mutual capacitances based on a maximum value of amutual capacitance among the plurality of mutual capacitances.
 16. Thedata processing apparatus of claim 11, wherein the at least oneprocessor is further configured to sequentially apply a driving signalto each of a plurality of driving electrodes included in the group, andobtain the first image data based on electrical signals measured from aplurality of detection electrodes included in the group.
 17. The dataprocessing apparatus of claim 11, wherein the at least one processor isfurther configured to determine a mutual capacitance at each of aplurality of nodes where each of a plurality of driving electrodesincluded in the group and each of a plurality of detection electrodesincluded in the group intersect.
 18. The data processing apparatus ofclaim 17, wherein the at least one processor is further configured todetermine a mutual capacitance in a second channel based on a mutualcapacitance in a region comprising a first channel and the secondchannel, wherein a fixed potential is applied to the first channel, andthe second channel is adjacent to the first channel.
 19. The dataprocessing apparatus of claim 11, wherein the at least one processor isfurther configured to generate a fingerprint image based on the secondimage data.